On World Environment Day, celebrated each year on June 5, the United Nations recognizes groups and individuals who have made outstanding contributions to the world environment with an award known as the Global 500 Roll of Honor. One of this year's Global 500 recipients is the Amazon Conservation Team. The group is based in the United States, but it is devoted to the protection of native cultures in the American tropics.

Mark Plotkin, the founder and director of the Amazon Conservation Team, likes to recall how a night class at Harvard University in 1974 changed the course of his life.

"I was actually totally fascinated by reptiles and wanted to grow up to be a herpetologist, but I opened the course catalog and saw a course on the botany and chemistry of hallucinogenic plants," he said. "Now this being the end of the 1960s, it had a certain appeal at the time. And so I enrolled in the class which was taught by this fabulous old Bostonian in a crew cut, wire rim glasses and a white laboratory coat who was showing slide after slide of these nearly naked peoples doing bizarre dances under the influence of these highly psychotropic plants." The professor, a world-renowned scientist who had explored the Amazon and lived with local Indian tribes, introduced Mark Plotkin to the field of ethnobotany, or the systematic study of people and plants. For 20 years, Mark Plotkin has worked as an ethnobotanist in the Amazon rainforest. He learned early on that indigenous people could play a critical role in rainforest conservation.

"The history of the conservation movement has really been anti-people in a way. Let's get these people out of the parks. Let's put the fences up. Let's protect the animals and maybe the plants. But if you think about it in terms of the indigenous peoples in the Amazon, the park guards are already there. Not only do these [indigenous] people live in the forest, which many park guards do not want to do, but they have a material tie in terms of their weapons, in terms if their houses, in terms of their hammocks," he said.

"But more importantly, they have a spiritual tie to the forest because that is where their sacred sites are. So I believe that harnessing their ties to the forest, basically empowering them to take control of their destiny, environmental, cultural, and spiritual, is the single most effective way of rationally utilizing the rainforest."

The cornerstone of the Amazon Conservation Team, which works in Brazil, Mexico, Colombia, Suriname, and Costa Rica, is an apprentice program where young members of indigenous tribes learn from their elder shaman healers, how to preserve their culture and environment.

"We have Shaman Apprentice clinics in the northeast Amazon, run by Shamans, assisted by apprentices, with American and local medical students working at the bottom rung of the totem pole to take clinical data. And they are drawing more patients than the missionary clinic."

VOA: "How does the Shaman Apprentice Program work?"

Plotkin: "What happens is young people in the tribe who decide they want to be apprentices volunteer for the program and essentially they are all taken on. After a year the shamans decide who is serious, who is observing the dietary taboos, the sexual taboos, the hunting taboos, who has a real predilection for healing, who really learns their plants, and then they make the first cut. You might say isn't it a shame that not everyone who wants to be a shaman gets to be a shaman, but then not everybody who wants to go to medical school gets to go to medical school. So we want that cream of the crop (the best students)."

Mr. Plotkin notes that alternative medicine, like that being taught by shamans in the Amazon, is becoming part of the curriculum in American medical schools.

"Columbia University has a program for alternative medicine in New York. Harvard has a program alternative medicine in Cambridge. So western medicine in their limitations is reaching out, but [it is] trying to find where the real healers are."

The Amazon region, with its unrivaled diversity of plants, is believed to be the world's greatest potential source of as yet-undiscovered medicines. Mark Plotkin says indigenous peoples are appropriate guardians of these lands and their biological riches.

"I think in the Amazon we have a chance to be proactive. Not to wait until the gold miners have invaded all the rainforest," he said. "Not to wait until all the forests have been cut down and then figure out what to do. I think that pro-active conservation is, at least in ideal terms, more effective and, perhaps as importantly, more cost effective. That is why the Amazon Conservation Team focuses on the Amazon, and I think that there are lessons we are learning that can be used with indigenous peoples and certainly in rainforests everywhere."

In addition to the success of the Shaman Apprentice Program the Amazon Conservation Team recently helped forge a deal with the Colombian government and indigenous peoples to establish a national park in a highly bio-diverse region of the country.

The native Indians, who have lived there for generations, will manage the park, a model the Amazon Conservation Team hopes to replicate in other places.

The Amazon Conservation Team is one of eight groups and individuals being honored on World Environment Day this year, with the United Nations Global 500 award.